1. Field of the Invention
This invention relates, generally, to devices attachable to vehicle tires to improve their traction in snow and ice.
2. Description of the Prior Art
The tire industry has developed tires especially suited for use in snowy and icy road conditions; such tires are known as snow tires and are generally characterized by deeper and wider treads as compared to the treads of fair weather tires.
The tire industry, recognizing the general inadequacy of snow tires in severe winter conditions, has also introduced tires having metal studs protruding from the tire surface. Such studded tires effectively grip icy roadways, but the entire tire must be removed when non-icy roads are encountered.
Inventors have accordingly developed many devices that are removably attachable to tires so that only the device and not the entire tire need be removed when roads become clear of snow and ice accumulation.
Perhaps the most widely-accepted innovation in this field of invention is the well-known arrangement of chains that may be wrapped around tires to increase their traction. Chains, though effective, are heavy and not easily installed. Motorists have been known to shun the chore of installing chains even when road conditions virtually mandated their use. Inventors have, therefore, sought alternative to chains.
Examples of devices that have been developed to overcome the limitations of chains are shown in the following U.S. Pat. Nos.:
______________________________________ U.S. Pat. No. Inventor Issue Date ______________________________________ 4,089,359 J. J. Jones May 16, 1978 3,891,018 E. Hyggen June 24, 1975 3,190,335 M. Isaacman June 22, 1965 2,873,783 M. O'Higgins February 17, 1959 2,767,761 M. O'Higgins October 23, 1956 2,730,406 G. C. Fitzgerald January 10, 1956 ______________________________________
Although the traction-enhancing devices of the prior art fulfill their intended purposes, they do so in a complex manner, i.e., the devices are mechanically complicated and as such are expensive to manufacture. The high manufacturing costs have resulted in high retail prices, which in turn have prevented the devices from gaining widespread acceptance in the marketplace.
There is a need for a quickly attachable and removable traction-enhancing device of elegant, low cost construction, but the prior art neither teaches nor suggests how the needed device could be constructed.